Kunii T, Hirao T, Kikuchi K, Tagami H
Department of Dermatology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
Br J Dermatol. 2003 Oct;149(4):749-56. doi: 10.1046/j.1365-2133.2003.05545.x.
The functional characteristics of the stratum corneum (SC) of fresh scars as well as keloids and hypertrophic scars are characterized by elevated transepidermal water loss (TEWL) and increased SC hydration.
To study the composition of the intercellular lipids and maturation properties of the cornified envelope (CE) of the SC, as these are the most important components for the SC barrier function in fresh scars.
SC lipids were extracted from the donor site for split-thickness skin grafting soon after re-epithelialization using a cup method, and were analysed with high-performance thin-layer chromatography. CEs, which were prepared from superficial layers of the SC, were double stained with Nile red and anti-involucrin.
We found a significant decrease in the proportion of ceramide (CER) in the SC lipids of fresh scars. We also observed changes in the SC CER profile that consisted of an increase in CER 4 and CER 7 and a decrease in CER 3, without any significant change in the proportion of CER 1. These changes were insufficient to explain the remarkably high TEWL recorded in the early stage of fresh scars. In contrast, with double staining of CE with Nile red and anti-involucrin, we detected the presence of numerous immature and less hydrophobic corneocytes in the outermost layer of the SC of fresh scars. Scanning electron microscopy of such corneocytes revealed numerous fine wrinkles on their enlarged surface area. Most of all, we found a closely similar, time-dependent, exponential decrease in the ratio of immature corneocytes with a poorly hydrophobic CE and in the recorded TEWL values in fresh scars. There was a highly significant positive correlation between the proportion of immature corneocytes in the outermost layer of the SC and TEWL values.
These results suggest that the SC barrier dysfunction of the fresh scars is attributable to the presence of immature corneocytes with a less hydrophobic CE, rather than to the changes in SC lipid composition.
新鲜瘢痕以及瘢痕疙瘩和增生性瘢痕的角质层（SC）的功能特征表现为经表皮水分流失（TEWL）升高和SC水合作用增加。
研究SC细胞间脂质的组成以及SC角质包膜（CE）的成熟特性，因为这些是新鲜瘢痕中SC屏障功能的最重要组成部分。
使用杯法在重新上皮化后不久从用于断层皮片移植的供皮区提取SC脂质，并用高效薄层色谱法进行分析。从SC表层制备的CE用尼罗红和抗内披蛋白进行双重染色。
我们发现新鲜瘢痕的SC脂质中神经酰胺（CER）的比例显著降低。我们还观察到SC CER谱的变化，包括CER 4和CER 7增加以及CER 3减少，而CER 1的比例没有任何显著变化。这些变化不足以解释新鲜瘢痕早期记录到的显著高TEWL。相比之下，用尼罗红和抗内披蛋白对CE进行双重染色时，我们在新鲜瘢痕SC的最外层检测到大量未成熟且疏水性较低的角质形成细胞。对这些角质形成细胞的扫描电子显微镜检查显示其扩大的表面积上有许多细纹。最重要的是，我们发现具有疏水性较差的CE的未成熟角质形成细胞比例与新鲜瘢痕中记录的TEWL值呈密切相似的、时间依赖性的指数下降。SC最外层未成熟角质形成细胞的比例与TEWL值之间存在高度显著的正相关。
这些结果表明，新鲜瘢痕的SC屏障功能障碍归因于存在具有疏水性较低的CE的未成熟角质形成细胞，而不是SC脂质组成的变化。
